Class Writer

Defined in File writer.hpp

Class Documentation

class Writer

The Writer allows writing messages to a new bag. For every topic, information about its type needs to be added before writing the first message.

Public Functions

explicit Writer(std::unique_ptr<rosbag2_cpp::writer_interfaces::BaseWriterInterface> writer_impl = std::make_unique<writers::SequentialWriter>())

~Writer()

void open(const std::string &uri)

Opens a new bagfile and prepare it for writing messages. The bagfile must not exist. This must be called before any other function is used.

See also

open, which let’s you specify more storage and converter options.

Note

This will open URI with the default storage options

using default storage backend
using no converter options, storing messages with the incoming serialization format

Parameters:: storage_uri – URI of the storage to open.

void open(const rosbag2_storage::StorageOptions &storage_options, const ConverterOptions &converter_options = ConverterOptions())

Opens a new bagfile and prepare it for writing messages. The bagfile must not exist. This must be called before any other function is used.

Parameters:

storage_options – Options to configure the storage
converter_options – options to define in which format incoming messages are stored

void close(): Close the current bag file and write metadata.yaml file.

void create_topic(const rosbag2_storage::TopicMetadata &topic_with_type)

Create a new topic in the underlying storage. Needs to be called for every topic used within a message which is passed to write(…).

Parameters:: topic_with_type – name and type identifier of topic to be created
Throws:: runtime_error – if the Writer is not open.

void create_topic(const rosbag2_storage::TopicMetadata &topic_with_type, const rosbag2_storage::MessageDefinition &message_definition)

Create a new topic in the underlying storage. Needs to be called for every topic used within a message which is passed to write(…).

Parameters:

topic_with_type – name and type identifier of topic to be created
message_definition – message definition content for this topic’s type

Throws:

runtime_error – if the Writer is not open.

bool take_snapshot()

Trigger a snapshot when snapshot mode is enabled.

Returns:: true if snapshot is successful, false if snapshot fails or is not supported

void split_bagfile(): Close the current bagfile and opens the next bagfile.

void remove_topic(const rosbag2_storage::TopicMetadata &topic_with_type)

Remove a new topic in the underlying storage. If creation of subscription fails remove the topic from the db (more of cleanup)

Parameters:: topic_with_type – name and type identifier of topic to be created
Throws:: runtime_error – if the Writer is not open.

void write(std::shared_ptr<const rosbag2_storage::SerializedBagMessage> message)

Write a message to a bagfile. The topic needs to have been created before writing is possible.

Parameters:: message – to be written to the bagfile
Throws:: runtime_error – if the Writer is not open.

void write(std::shared_ptr<const rosbag2_storage::SerializedBagMessage> message, const std::string &topic_name, const std::string &type_name, const std::string &serialization_format = "cdr")

Write a message to a bagfile. The topic will be created if it has not been created already.

Parameters:

message – to be written to the bagfile
topic_name – the string of the topic this messages belongs to
type_name – the string of the type associated with this message
serialization_format – the format in which this message is serialized

Throws:

runtime_error – if the Writer is not open.

void write(const rclcpp::SerializedMessage &message, const std::string &topic_name, const std::string &type_name, const rclcpp::Time &time)

Write a serialized message to a bagfile. The topic will be created if it has not been created already.

Parameters:

message – rclcpp::SerializedMessage The serialized message to be written to the bagfile
topic_name – the string of the topic this messages belongs to
type_name – the string of the type associated with this message
time – The time stamp of the message

Throws:

runtime_error – if the Writer is not open or duplicating message is failed.

void write(std::shared_ptr<const rclcpp::SerializedMessage> message, const std::string &topic_name, const std::string &type_name, const rclcpp::Time &time)

Write a serialized message to a bagfile. The topic will be created if it has not been created already.

Warning

after calling this function, the serialized data will no longer be managed by message.

Parameters:

message – rclcpp::SerializedMessage The serialized message to be written to the bagfile
topic_name – the string of the topic this messages belongs to
type_name – the string of the type associated with this message
time – The time stamp of the message

Throws:

runtime_error – if the Writer is not open.

template<class MessageT> inline void write(const MessageT &message, const std::string &topic_name, const rclcpp::Time &time)

Write a non-serialized message to a bagfile. The topic will be created if it has not been created already.

Parameters:

message – MessageT The serialized message to be written to the bagfile
topic_name – the string of the topic this messages belongs to
type_name – the string of the type associated with this message
time – The time stamp of the message

Throws:

runtime_error – if the Writer is not open.

inline writer_interfaces::BaseWriterInterface &get_implementation_handle() const

void add_event_callbacks(bag_events::WriterEventCallbacks &callbacks)